Search Results

Search found 7805 results on 313 pages for 'high voltage'.

Page 198/313 | < Previous Page | 194 195 196 197 198 199 200 201 202 203 204 205  | Next Page >

• Implementing a linear, binary SVM (support vector machine)

  - by static_rtti

  I want to implement a simple SVM classifier, in the case of high-dimensional binary data (text), for which I think a simple linear SVM is best. The reason for implementing it myself is basically that I want to learn how it works, so using a library is not what I want. The problem is that most tutorials go up to an equation that can be solved as a "quadratic problem", but they never show an actual algorithm! So could you point me either to a very simple implementation I could study, or (better) to a tutorial that goes all the way to the implementation details? Thanks a lot!

  Read the article

• How to recover gracefully from a C# udp socket exception

  - by Gearoid Murphy

  Context: I'm porting a linux perl app to C#, the server listens on a udp port and maintains multiple concurrent dialogs with remote clients via a single udp socket. During testing, I send out high volumes of packets to the udp server, randomly restarting the clients to observe the server registering the new connections. The problem is this: when I kill a udp client, there may still be data on the server destined for that client. When the server tries to send this data, it gets an icmp "no service available" message back and consequently an exception occurs on the socket. I cannot reuse this socket, when I try to associate a C# async handler with the socket, it complains about the exception, so I have to close and reopen the udp socket on the server port. Is this the only way around this problem?, surely there's some way of "fixing" the udp socket, as technically, UDP sockets shouldn't be aware of the status of a remote socket? Any help or pointers would be much appreciated. Thanks.

  Read the article

• Fastest sort of fixed length 6 int array

  - by kriss

  Answering to another StackOverflow question (this one) I stumbled upon an interresting sub-problem. What is the fastest way to sort an array of 6 ints ? As the question is very low level (will be executed by a GPU): we can't assume libraries are available (and the call itself has it's cost), only plain C to avoid emptying instruction pipeline (that has a very high cost) we should probably minimize branches, jumps, and every other kind of control flow breaking (like those hidden behind sequence points in && or ||). room is constrained and minimizing registers and memory use is an issue, ideally in place sort is probably best. Really this question is a kind of Golf where the goal is not to minimize source length but execution speed. I call it 'Zening` code as used in the title of the book Zen of Code optimization by Michael Abrash and it's sequels.

  Read the article

• Troubles configuring SSL for an Apache host

  - by Ryan

  I configured it on Friday night and all worked well. Today for some reason it stopped working and I can't figure out why. When you goto the secure page it's acting like I have a self-signed certificate and I don't. I have the host configured like so ServerAdmin [email protected] DocumentRoot "/path/to/site" Servername www.mydomain.com ServerAlias mydomain.com DirectoryIndex index.cfm index.htm SSLEngine on SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL SSLCertificateFile /etc/httpd/path/to/mydomain.com.crt SSLCertificateKeyFile /etc/httpd/path/to/www.mydomain.com.key SSLCertificateChainFile /etc/httpd/path/to/gd_bundle.crt Apache starts with no errors and I can't seem to find anything meaningful in any of the logs. It's got to be something minor but I can't seem to see it. It's an updated Centos/Apache VM. I have worn Google out.

  Read the article

• How do I make "simple" throughput servlet-filter?

  - by Tommy

  I'm looking to create a filter that can give me two things: number of request pr minute, and average responsetime pr minute. I already got the individual readings, I'm just not sure how to add them up. My filter captures every request, and it records the time each request takes: public void doFilter(ServletRequest request, ...() { long start = System.currentTimeMillis(); chain.doFilter(request, response); long stop = System.currentTimeMillis(); String time = Util.getTimeDifferenceInSec(start, stop); } This information will be used to create some pretty Google Chart charts. I don't want to store the data in any database. Just a way to get current numbers out when requested As this is a high volume application; low overhead is essential. I'm assuming my applicationserver doesn't provide this information.

  Read the article

• geographical deployment Vs geo load balancing SharePoint 2010

  - by vrajaraman

  we have a company wide SharePoint portals planned for few thousand users. since the users are distributed among different countries and their applications (hosted in sharepoint) We would like to consider geo deployment Vs geo load balancing. Please share your inputs. We are aware of this, Geo SharePoint Cluster facilitates - Farms at Central and other sites , db into regional. 2 db cluster - syncing using logshipping or SAN sync or SQL 2008 features like database mirroing Vs Loading balancing using URL and some 3rd party. all farm,sites,db centralised. benefits expecting. 1 High availability. 2.diaster recovering management. 3.maintenance hope i miss some of the points to be covered

  Read the article

• Indexing only one MySQL column value

  - by BrainCore

  I have a MySQL InnoDB table with a status column. The status can be 'done' or 'processing'. As the table grows, at most .1% of the status values will be 'processing,' whereas the other 99.9% of the values will be 'done.' This seems like a great candidate for an index due to the high selectivity for 'processing' (though not for 'done'). Is it possible to create an index for the status column that only indexes the value 'processing'? I do not want the index to waste an enormous amount of space indexing 'done.'

  Read the article

• Why darcs instead of git?

  - by Ctrl Alt D-1337

  Using pure functional languages can have a lot of benefits over using impure imperatives but low level systems languages will generally allow you to achieve much greater performance especially when they are imperative because it allows you to specify the exact steps in how the cpu should compute the result. If there is ever list of tools where high performance is an absolute must then I would put source version controls systems right at the top of that list and git achieves this very well but performance is not it's only advantage over many other other types of version control systems anyway. The git team are handling the unsafe c code very well and I never worry about my type system or any other features of the language it is written in so why is it that there is a lot of haskell developers that must use darcs when they will only be using the finished product?

  Read the article

• Only show activities from a specific gadget in OpenSocial

  - by corné

  I created a gadget which is able to post activities: function postActivity(text) { var params = {}; params[opensocial.Activity.Field.TITLE] = text; var activity = opensocial.newActivity(params); opensocial.requestCreateActivity(activity, opensocial.CreateActivityPriority.HIGH); }; And I request activities by doing: req.add(req.newFetchActivitiesRequest( new opensocial.IdSpec({'userId' : 'VIEWER', 'groupId' : 'FRIENDS'})), 'friends_activities'); My question is: How can I filter activities to only show activities posted by a specific gadget? I reckon the field "appId" is meant for this, but this field is empty in the response.

  Read the article

• Quickest and easiest way to implement speech to text conversion for a small speech subset.

  - by sgtpeppers

  Hi, I want to implement a system that receives speech through a microphone on my Mac OS x. I know arbitrary speech recognition is close to impossible without training the system so I'm willing to restrict it to 10 simple sentences. It must recognize with a high degree of accuracy which of these 10 sentences are being spoken, generate the text and add an entry to a remote MySQL database. With these being the architecture of the system I want to implement, could anyone give me an overview of what would be the best way to go about implementing this system? I'm looking for ideas like open source libraries to minimize the coding as this is just a prototype application for a demonstration. Basically I'm looking for a quick and easy solution. Thanks!

  Read the article

• How to resolve this very heavy query that slows down the application?

  - by Juan Paredes

  Hi, We have a web application running in a production enviroment and at some point the client complained about how slow the application got. When we checked what was going on with the application and the database we discover this "precious" query that was being executed by several users at the same time (thus inflicting a extremely high load on the database server): SELECT NULL AS table_cat, o.owner AS table_schem, o.object_name AS table_name, o.object_type AS table_type, NULL AS remarks FROM all_objects o WHERE o.owner LIKE :1 ESCAPE :"SYS_B_0" AND o.object_name LIKE :2 ESCAPE :"SYS_B_1" AND o.object_type IN(:"SYS_B_2", :"SYS_B_3") ORDER BY table_type, table_schem, table_name Our application does not execute this query, I believe it is an Hibernate internal query. I've found little information on why Hibernate does this extremely heavy query, so any help is very much appreciated! The production enviroment information: Red Hat Enterprise Linux 5.3 (Tikanga), JDK 1.5, web container OC4J (whitin Oracle Application Server), Oracle Database 10g Release 10.0.0.1, JDBC Driver for JDK 1.2 and 1.3, Hibernate version 3.2.6.ga. Thank you.

  Read the article

• Suggest Cassandra data model for an existing schema

  - by Andriy Bohdan

  Hello guys! I hope there's someone who can help me suggest a suitable data model to be implemented using nosql database Apache Cassandra. More of than I need it to work under high loads and large amounts of data. Simplified I have 3 types of objects: Product Tag ProductTag Product: key - string key name - string .... - some other fields Tag: key - string key name - unique tag words ProductTag: product_key - foreign key referring to product tag_key - foreign key referring to tag rating - this is rating of tag for this product Each product may have 0 or many tags. Tag may be assigned to 1 or many products. Means relation between products and tags is many-to-many in terms of relational databases. Value of "rating" is updated "very" often. I need to be run the following queries Select objects by keys Select tags for product ordered by rating Select products by tag order by rating Update rating by product_key and tag_key The most important is to make these queries really fast on large amounts of data, considering that rating is constantly updated.

  Read the article

• Strategies to use Database Sequences?

  - by Bruno Brant

  Hello all, I have a high-end architecture which receives many requests every second (in fact, it can receive many requests every millisecond). The architecture is designed so that some controls rely on a certain unique id assigned to each request. To create such UID we use a DB2 Sequence. Right now I already understand that this approach is flawed, since using the database is costly, but it makes sense to do so because this value will also be used to log information on the database. My team has just found out an increase of almost 1000% in elapsed time for each transaction, which we are assuming happened because of the sequence. Now I wonder, using sequences will serialize access to my application? Since they have to guarantee that increments works the way they should, they have to, right? So, are there better strategies when using sequences? Please assume that I have no other way of obtaining a unique id other than relying on the database.

  Read the article

• JD Edwards... call C#?

  - by rbobby

  Hey all, I know very little about JD Edwards. I have a client asking how to call an API we supply (as COM, C#, REST) from JD Edwards. I'm not getting much in terms of high quality answers from their tech guy... so I thought I'd ask here. Can JD Edwards call C#? Can JD Edwards call Java? Can JD Edwards call a Unix scipt? Can anyone point me towards anything useful in terms of developer/customization documentation? Thanks!

  Read the article

• Subclassing UIScrollView for drawing w/o views

  - by David Dunham

  I'm contemplating subclassing UIScrollView (the way UITextView does) to draw a fairly large amount of text (formatted in ways that NSTextView can't). So far the view won't actually scroll. I'm setting contentSize, and when I drag, I see the scroll indicator. But nothing changes (and I don't get a drawRect: message). An alternate approach is to use a child view, and I've done this. The view can be over 5000 pixels high, however, and I'm a bit concerned about performance on an actual device. (The other approach, be like UITableView, would be a huge pain -- I'm "porting" Mac Cocoa code, and a collection of views would be a huge architecture change.) I've done some searching, but haven't found anyone who is using UIScrollView to do the drawing. Has anyone done this and know of any pitfalls?

  Read the article

• Minimum Acceptable Code Coverage Numbers in the real world.

  - by Pita.O

  Hi, I am in the middle of putting together some guidelines around code coverage and I want to specify a number that really makes sense. It's easy to repeat the 100% mantra that I see all over the internet without considering the cost benefit analysis and when diminishing returns actually sets in. I solicit comments from persons who have actually reported code coverage on real-life, medium/large-sized projects. What percentages were you seeing? How much is too much? I really want some balance (in figures) that will help developers produce hight quality code. Is 65% coverage too low to expect? Is 80% too high?

  Read the article

• What Simple Changes Made the Biggest Improvements to Your Delphi Programs

  - by lkessler

  I have a Delphi 2009 program that handles a lot of data and needs to be as fast as possible and not use too much memory. What small simple changes have you made to your Delphi code that had the biggest impact on the performance of you program by noticeably reducing execution time or memory use? Thanks everyone for all your answers. Many great tips. For completeness, I'll post a few important articles on Delphi optimization that I found. Before you start optimizing Delphi code at About.com Speed and Size: Top 10 Tricks also at About.com Code Optimization Fundamentals and Delphi Optimization Guidelines at High Performance Delphi, relating to Delphi 7 but still very pertinent.

  Read the article

• LNK1106 with big binary resource

  - by E Dominique

  I have a rather huge .dat-file (896MB) included as a BIN resource in my project. Now I get a LNK1106 link error ("fatal error LNK1106: invalid file or disk full: cannot seek to 0x382A3920".) I use Visual Studio 2005 under Windows XP, and have tried on a 4GB RAM machine with high Virtual Memory settings and lots of disk space. I have tried a number of different optimization flags, but to no avail. Does anyone have a clue? EDIT: I have narrowed it down to a specific size of the compiled resource. If the .res file is 544078588 bytes (about 518.9MB) or larger, the error occurs. If it is smaller it works just fine. Still no solution, though...

  Read the article

• w3wp.exe in ASP.NET production app is using 100% CPU. How to find the problem ?

  - by Tucker

  Hi, we have an asp.net app in production where w3wp.exe is taking 100% CPU ( 4 cores - 4 threads at 25% ) and cpu load never goes down until we recycle the application pool ( the app is alone in the application pool ). Our error log has nothing, there is no exceptions being emitted ( or at least we don't catch them ) so we suspect it's code problem ( infinite loop / deadlock ). The problem only arises after some hours running with high load ( several thousand users ). There is any way to profile one of the EXISTING threads that is causing cpu load ? After taking a look to JetBrains's DotTrace Profiler seems like it's not possible for limitations of Profiling API and man, we haven't get to reproduce the problem in our testing environment. The app uses SQL Server 2005, LINQ2SQL and System.Transactions API. Any suggestion to find the problem ?

  Read the article

• typesafe NotifyPropertyChanged using linq expressions

  - by bitbonk

  Form Build your own MVVM I have the following code that lets us have typesafe NotifyOfPropertyChange calls: public void NotifyOfPropertyChange<TProperty>(Expression<Func<TProperty>> property) { var lambda = (LambdaExpression)property; MemberExpression memberExpression; if (lambda.Body is UnaryExpression) { var unaryExpression = (UnaryExpression)lambda.Body; memberExpression = (MemberExpression)unaryExpression.Operand; } else memberExpression = (MemberExpression)lambda.Body; NotifyOfPropertyChange(memberExpression.Member.Name); } How does this approach compare to standard simple strings approach performancewise? Sometimes I have properties that change at a very high frequency. Am I safe to use this typesafe aproach? After some first tests it does seem to make a small difference. How much CPU an memory load does this approach potentially induce?

  Read the article

• PHP application variable... maybe?

  - by James

  I went to a PHP job interview, I was asked to implement a piece of code to detect visitors are bots to crawl thru the website and steal content. So I implemented a few lines of code to detect if the site is being refreshed/visited too quickly/often by using a session variable to store last visit timestamp. I got told that session varaibles can be manupilated by cookies etc, so I am wondering if there is a application variable that I can use to store the timestamp information against visitor IPs eg $_SERVER[REMOTE_ADDR]? I know that I can write the data to a file but it's not very good for a high traffic website. Regards James

  Read the article

• OpenCL: does it play well with OpenMP, can I connect other languages to it, etc.

  - by Cem Karan

  The 1.0 spec for OpenCL just came out a few days ago (Spec is here) and I've just started to read through it. I want to know if it plays well with other high performance multiprocessing APIs like OpenMP (spec) and I want to know what I should learn. So, here are my basic questions: If I am already using OpenMP, will that break OpenCL or vice-versa? Is OpenCL more powerful than OpenMP? Or are they intended to be complementary? Is there a standard way of connecting an OpenCL program to a standard C99 program (or any other language)? What is it? Does anyone know if anyone is writing an OpenCL book? I'm reading the spec, but I've found books to be more helpful.

  Read the article

• Developing Mobile App (Iphone,Blackberry,Android) for an existing website

  - by soodos

  Hey Guys I have a website and am planning to develop a mobile version of it for the iphone, blackberry and android. My website is a social network built on PHP Zend framework. Now all these mobile apps are going to be having the same functionality like the website. I am little ignorant about this - but from a high level I understand that all these mobile apps should not have to write any backend logic. For every functionality - they will simply make a web service API call to interact with the backend. So does that mean, for every functionality I need to create a web service method. Can the existing code be re used - I'm a little lost - Can someone shed some light on this matter or point me in the right direction (like some articles) Thanks

  Read the article

• From admin to dev [closed]

  - by Terry

  Recently a friend of mine had gone from a high level NOC position to a developer. Before that he was just doing the help desk stuff. He has no degree, only the usual MIS/networking certifications and as far as I know only tinkers with code on the weekends. I can see where in some scenarios having a good understanding of configurations, packets, users, OU's, etc would be extremely beneficial to a developer. My question is this, how many full time developers started off this way? Even how many people dual wield the responsibility of developer/systems administrator/network administration?

  Read the article

• How to put a newline into a column header in an xtable in R

  - by PaulHurleyuk

  I have a dataframe that I am putting into a sweave document using xtable, however one of my column names is quite long, and I would like to break it over two lines to save space calqc_table<-structure(list(RUNID = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), ANALYTEINDEX = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), ID = structure(1:11, .Label = c("Cal A", "Cal B", "Cal C", "Cal D", "Cal E", "Cal F", "Cal G", "Cal H", "Cal High", "Cal Low", "Cal Mid"), class = "factor"), mean_conc = c(200.619459644855, 158.264703128903, 102.469121407733, 50.3551544728544, 9.88296440865076, 4.41727762501703, 2.53494715706024, 1.00602831741361, 199.065054555735, 2.48063347296935, 50.1499780776199), sd_conc = c(2.3275711264554, NA, NA, NA, NA, NA, NA, 0.101636943231162, 0, 0, 0), nrow = c(3, 1, 1, 1, 1, 1, 1, 3, 2, 2, 2)), .Names = c("Identifier of the Run within the Study", "ANALYTEINDEX", "ID", "mean_conc", "sd_conc", "nrow"), row.names = c(NA, -11L ), class = "data.frame") calqc_xtable<-xtable(calqc_table) I have tried putting a newline into the name, but this didn't seem to work names(calqc_table)[1]<-"Identifier of the \nRun within the Study" Is there a way to do this ? I have seen someone suggest using the latex function from the hmisc package to manually iterate over the table and write it out in latex manually, including the newline, but this seems like a bit of a faf !

  Read the article

< Previous Page | 194 195 196 197 198 199 200 201 202 203 204 205  | Next Page >